Sen. Pat Toomey said Friday that the simplification in the new tax code comes from how you define income rather than the number of tax brackets.

“The way I look at the tax returns for an individual, for a family, I think how you define the income is more important than how many brackets you have,” Mr. Toomey, Pennsylvania Republican, on Fox News. “And so by simplifying the process of defining it, you’re going to be able to fill out your tax return on one page.”

The Senate released its version of the bill Thursday, which differs slightly from the House plan. While the House plan limits the number of brackets to four, the Senate keeps the current seven brackets and reduces the rate of each bracket.

Mr. Toomey said he’s confident Republicans will come together and pass a tax plan.

“I feel very good about it. We’ve rolled it out among Republican senators. Our Democratic colleagues, some of them are just reflexively — they were opposing it before it was written — so that was predictable for some,” Mr. Toomey explained. “But there’s others that have taken a hard look at it. I think we’re going to pass it.”

Democrats have remained nearly unanimously opposed to the bill, arguing that it is a tax cut for wealthy corporations and those in the top-tier brackets.

Republicans remain committed to passing a bill for President Trump to sign before the end of the year.